John D Smith,
I want to think the Li battery was good for more than 500 charges. 500 is more like a Ni-cd.
Here is the deal, there is only one charger made by dewalt that will charge Ni-MH, Li-ion, and Ni-cd. There is no fast or slow setting. I have 3 other batteries, one Li and 2 Ni-Mh. So far, they seem to be OK. Only time will tell me which is the better battery.
When I run a battery down, it put in the truck to cool off for a few hours before I charge. I have a charger in the truck that runs off the truck's battery, 2 chargers that connect to 120v and two other chargers built in to the dewalt work radios. Don't think I can blame the chargers or temperature for the failure. BTW, if any battery is too cold, I have to warm it up with the truck's heater before it will take a charge. So many times, I'm driving and charging.
I think the problem is the Lithium battery. NEVER did like them. Compared to the Ni-Mh, they are wimps.
I think Boeing may share my opinion. They are saying thermal runaway may be the dreamliner's nightmare.
Is there a next generation Lithium battery? Saw a lithium battery on something at sears and it looked many times smaller.